Conference Paper

Dynamic Event Trees without Success Criteria. Application to Full Spectrum LOCA sequences. Calculation of Damage Exceedance Frequency with Integrated Safety Assessment (ISA) Methodology

In proceeding of: 38 Annual Meeting Nuclear Spanish Society

ABSTRACT The Integrated Safety Assessment (ISA) methodology, developed by the Spanish Nuclear Safety Council (CSN), has been applied to obtain the Dynamic Event Trees (DETs) for Full Spectrum Loss of Coolant Accidents (LOCAs) of a Westinghouse 3-loop PWR plant. The purpose of this ISA application is to obtain the Damage Exceedance Frequency (DEF) for the LOCA Event Tree by taking into account the uncertainties in the break area and the operator actuation time needed to cool down and depressurize reactor coolant system by means of steam generators. Simulations are performed with SCAIS, a software tool which includes a dynamic coupling with MAAP thermal hydraulic code. The results show the capability of the ISA methodology to obtain the DEF taking into account the time uncertainty in human actions.

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May 31, 2014